condition mean min max ZT0-3 704.464661 704.464661 704.464661 ZT4-7 603.325929 603.325929 603.325929 ZT8-11 739.625803 739.625803 739.625803 ZT12-15 754.530759 754.530759 754.530759 ZT16-19 817.8609235 817.8609235 817.8609235 ZT20-23 790.1608075 790.1608075 790.1608075